A common ophthalmological surgical technique is the removal of a diseased or injured lens from the eye. Earlier techniques used for the removal of the lens typically required a substantial incision to be made in the capsular bag in which the lens is encased. Such incisions were often on the order of 12 mm in length.
Later techniques focused on removing diseased lenses and inserting replacement artificial lenses through as small an incision as possible. For example, it is now a common technique to take an artificial intraocular lens (IOL), fold it and insert the folded lens through the incision, allowing the lens to unfold when it is properly positioned within the capsular bag. Similarly, efforts have been made to accomplish the removal of the diseased lens through an equally small incision.
One such removal technique is known as phacoemulsification. A typical phacoemulsification tool includes a handpiece to which is attached a hollow needle. Electrical energy is applied to vibrate the needle at ultrasonic frequencies in order to fragment the diseased lens into small enough particles to be aspirated from the eye through the hollow needle. Commonly, an infusion sleeve is mounted around the needle to supply irrigating liquids to the eye in order to aid in flushing and aspirating the lens particles.
It is extremely important to properly infuse liquid during such surgery. Maintaining a sufficient amount of liquid prevents collapse of certain tissues within the eye and attendant injury or damage to delicate eye structures. As an example, endothelial cells can easily be damaged during such collapse and this damage is permanent because these cells do not regenerate. One of the benefits of using as small in incision as possible during such surgery is the minimization of leakage of liquid during and after surgery and the prevention of such a collapse.
Phacoemulsification needles and tips are well represented in the prior art. Needles and tips of varying configurations are well known. A particular shape for a tip or needle is often dictated by the type of handpiece with which the needle is to be used.
United States Patent Application Publication 2006/0217672 (Chon) teaches and describes a phacoemulsification tip that is swaged or crimped at its distal end. The tip is intended for use with a handpiece producing torsional motion and the crimping forms cutting edges at the distal end.
U.S. Pat. No. 5,725,495 (Strukel et al) teaches and describes a phacoemulsification handpiece, sleeve and tip illustrating a wide variety of tip configurations and needle cross-sectional configurations.
U.S. Pat. No. 6,007,555 (Devine) teaches and describes an ultrasonic needle for surgical emulsification. The needle and its tip are shown in both circular and oval configurations.
U.S. Pat. No. 6,605,054 (Rockley) teaches and describes a multiple bypass port phaco tip having multiple aspiration ports and a single discharge port to infuse liquid into the eye.
U.S. Pat. No. 5,879,356 (Geuder) teaches and describes a surgical instrument for crushing crystalline eye lenses by means of ultrasound and for removing lens debris by suction which demonstrates the use of a sleeve positioned concentric to the needle and having a pair of discharge ports formed thereon.
U.S. Pat. No. 5,645,530 (Boukhny) teaches and describes a phacoemulsification sleeve, one variation of which has a bellows portion attached to a discharge port ring which directs an annular flow of liquid around the needle and into the eye. The use of the bellows is intended to allow the sleeve to absorb spikes in liquid pressure during the operation.
Published U.S. Patent Application No. 2003/0004455 (Kadziauskas) teaches and describes a bi-manual phaco needle using separate emulsification and aspiration needles inserted into the eye simultaneously during surgery.
U.S. Pat. No. 6,077,285 (Boukhny) teaches and describes a torsional ultrasound handpiece configured to impart both longitudinal and torsional motion to a phacoemulsification needle.
U.S. Pat. No. 6,402,769 (Boukhny) is a continuation in part of the '285 patent and further particularizes the frequencies at which the crystals providing both the torsional and longitudinal motion are activated.
I have determined that improved results can be achieved if the phacoemulsification tip is provided with more than one aspiration lumen. I have also determined that these improved results can be achieved using the straight phacoemulsification needle configuration, a configuration which is favored by a considerable number of doctors.
In addition, the tip design is expected to enhance the emulsifying defect created by a phacoemulsification handpiece imparting torsional motion to a phacoemulsifcation needle. Improved results are also anticipated when the present invention is used with a phacoemulsifcation handpiece providing longitudinal motion.
In accordance with an example of the apparatus, a phacoemulsification needle is provided for use with a phacoemulsification handpiece with the needle having at least two aspiration lumens formed proximate the needle tip opening. Preferably, both lumens communicate with a central aspiration passageway formed in the needle body.
While the following describes an example or examples of the present invention, it is to be understood that such description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures